Curiosity Rover Closing in on Mars

The next Mars rover, launched last November, is closing in on its target. NASA announced this week that the Mars Science Laboratory, or Curiosity, is right on schedule and explained more of the rover's mission.

It's now less than two months until the Mars Science Lab, better known as MSL or Curiosity, is due to touch down on the Red Planet. At a teleconference yesterday, NASA researchers and engineers reported that Curiosity's journey toward the Red Planet was going smoothly and revealed more details about what Curiosity will do once it touches down.

MSL's predecessors, the Spirit and Opportunity rovers, were intended for missions of just a few months, though they kept roving for years. Curiosity is intended from the beginning to drive around for at least one Martian year, which about 1.88 Earth years.

While there, Curiosity will continue to search for evidence of life but with even more attention to detail than previous missions could muster, says John Grotzinger, an MSL project scientist at CalTech. MSL will debut the Sample Analysis at Mars Instrument Suite, or SAM. A combination of three different pieces of lab equipment, the device can both scan Mars' atmosphere with a laser spectrometer, as well as vaporize and analyze the contents of nearby rocks and soil with both a gas chromatograph and a mass spectrometer. All three of these instruments will be used to detect methane and other carbon-containing molecules.

Also on board Curiosity is the Dynamic Albedo of Neutrons, or DAN, a way to map ice that may be hidden beneath the Martian surface. Cosmic rays from space strike the surface of Mars and scatter neutrons into the atmosphere. However, if ice is present in the upper 2 meters of the Martian surface, it interferes with the penetrating cosmic rays, and the scattered neutrons will have less energy. DAN will measure the energy levels of neutrons as the rover travels around, providing geographical data on which areas on Mars contain ice.

The rover is expected to land on Mars on August 5 at 10:31 pm PDT. We won't even know right away whether it safely landed on the planet or not. According to Pete Theisinger, one of the MSL's project managers, even in perfect conditions, light will take approximately 14 minutes to travel from Mars to Earth on MSL's scheduled landing date. The lag could even be as long as a day or two if the communications equipment isn't running perfectly. Given the complicated tasks that Curiosity is expected to do, most people should expect the lag.

"The early going will seem slow compared to the Spirit and Opportunity missions," Theisinger says. "We have a marathon, not a sprint."